I put Evans NPG+ in both my 300D's, starting a year ago, after seeing Ed China promote waterless on Wheeler Dealers, plus Jay Leno. My main motivation was to avoid corrosion. What is the time & effort to change a heater core in these cars? I haven't noticed higher temperatures. My son did see 105 C climbing the I-5 grade to LA on a hot day, whereas the car normally runs at 85 C, but still in the safe zone and don't recall what it did with 50/50 coolant before.

Re hose leaks, it runs with no pressure so a hose probably won't burst and lose it all while driving. If I need to work on the cooling system, I recover it and reuse. I run it thru a simple filter (wife's nylon stocking). I carry 1/2 gal in the trunk. No sense contaminating it with the water I spent so much time purging (easier in our hot, dry summers).